Project Summary/Abstract Potentiometric Probes Voltage-sensitive dyes can be applied to brain cells and tissue to study the electrical signals used by the brain to function. The fluorescent dye molecules light up under a microscope and convert tiny electrical signals to measurable changes in light intensity. All neurological disorders involve changes in the brain?s normal electrical activity and can potentially be studied with voltage-sensitive dyes. Potentiometric Probes is working to develop voltage-sensitive dyes that are easy enough to use in virtually any academic or pharmaceutical industry research lab studying the brain?s electrical signaling. To make this possible the dyes should be as sensitive as possible to voltage to provide a readout that is both very fast and clear. Potentiometric Probes has developed a new voltage-sensitive dye technology that can potentially meet this goal and deliver the sensitivity required. If successful, this would make voltage imaging accessible to a much wider body of researchers and provide them with a more powerful tool for studying the electrical signals underlying normal and pathological brain function. One day, dyes may even be used in human patients to help diagnose and better treat neurological disorders.